I wish that was the case. TDC (the largest danish telco) actually sold information about mobile users, including roaming users to VisitAarhus. Specifically, it was data about the locations of mobile users.
Telia did the same thing in Sweden some years ago. There are however ISPs who have a business model based on them having a very high profile in personal integrity politics (like Bahnhof), which I would feel more comfortable with thanany other DNSs
By wouldn’t you expect Bahnhof to offer a DoH-capable resolver for its customers then, that you could use in FF if you choose to enable the feature once it’s out of the experimental phase?
Danish article on the subject: https://www.version2.dk/artikel/tdc-saelger-data-mobilbruger...
So there is still plenty of reasons not to trust your ISP in Denmark and Europe in general.